1. Field of the Invention
The invention relates generally to methods and devices for animal slaughter contamination control, specifically to patches for sealing the vents of food animal carcasses, whereby preventing spilling of urine and fecal matter contained in the intestinal tract onto or into the carcass.
2. Description of the Prior Art
The urine and fecal matter contained in the intestines and uterus of beef and pork carcasses can seriously contaminate the otherwise bacteria-free meat if they are not kept separate and contained. Various types of bacteria are found in the intestines of butchered animals and such bacteria is often toxic to consumers of the meat and also can prematurely spoil the meat. Such bacteria in cattle includes E. coli 0157:H7, and other deadly strains that can withstand some traditional food-processing techniques. So government regulations strictly control the acceptable levels of bacteria in the finished meat products. Some have proposed irradiation of meat as a way to control such contamination. But others concerned with the hazards of the irradiation process itself to workers have taken the position that the problems should be controlled at the source, e.g., using better butchering methods.
The natural vents of the animals, e.g., the anus and vagina, are the only natural outlets for the intestines and uterus of beef and pork carcasses during slaughter, so care must be taken not to nick or cut the organs after the vents are sealed. If the organs and vents can be cut out of the carcass as a single unit without spilling any of the liquid contaminants on the remaining meat, the control of bacterial infection in the meat is greatly simplified.
Fecal contamination is particularly problematic with poultry animals as the animals are submerged in mass in tanks of hot water during processing to help loosen feathers. The carcasses are tanked a second time in cold water to chill the carcasses. USDA regulations require carcasses which have fecal matter on them, as evidenced by staining or discoloration, to be quarantined and reworked prior to being allowed back into production. The chances of severe bacterial contamination are increased by making the two trips through the water baths. Individual animals which have fecal matter on the carcass or fecal matter that leaks from the animals contaminates the whole of the tank water. This form of contamination is difficult and expensive to detect, as it requires biological testing which often takes hours to obtain final results. Large numbers of carcasses can be contaminated by only a few leaking ones that create a "fecal soup".
Poultry vents are relatively simple to seal, since the vents are much smaller than those in beef and pork carcasses. U.S. Pat. Nos. 5,083,975, issued Jan. 28, 1992, 5,120,267, issued Jan. 9, 1992, and 5,292,278, issued Mar. 8, 1994, all to Neal, et al., describe adhesives and methods for gluing the vent tissues of poultry and fowl carcasses to prevent fecal leakage during processing. Such disclosures are incorporated herein by reference.
U.S. Pat. No. 5,114,380, issued May 19, 1992, describes the use of an anal plug in a method for eviscerating animal carcasses. But such describes freezing of the anus to an inserted plug, and as such is complicated and is still nevertheless not immune from leakage of contaminants.
Increasing government scrutiny and testing of meat products at the retail level now demands that better slaughtering methods be employed to reduce the traditionally high levels of meat contamination.